To be cost efficient in operation of a high production system, such as stamping, molding, machining, and the like, it is requisite that fixture exchange time be minimal so as to hold to a minimum, or eliminate, downtime. This is especially true in a highly automated molding system where the physical and chemical state of the materials worked on presents additional down-time problems.
Operations involving the movement of fixtures of substantial size and/or weight are typically cumbersome and time-consuming, especially when the fixtures must be secured to a work surface after placement or repositioning thereon. Exact positioning of the fixture is often critical in achieving the desired results from the fixture and can be difficult to achieve with sizable, heavy fixtures. Further, the removal of such sizable fixtures involves laborious, time-consuming efforts to unsecure and remove the fixture from the work surface. The effort required to move such fixtures results in reduction of the rate of operations, increased labor expenses, and decreased flexibility in scheduling operations requiring different fixtures.
In the field of molding, e.g., injection molding and thermoforming, various sizes of molds are used to produce different products. The commercially used molds are typically quite heavy and cumbersome to move. The mount plates used to trim the products resulting from the thermoforming differ for each product and likewise are often of substantial size and/or weight. Most commercial operations routinely involve the production of a variety of molded products to meet customer requests. The amount of the product varies and the molds are changed according to the amount required of a particular product. The diversification of products as well as varying customer requests often requires frequent change of the molds or dies used in molding and associated operations. Further, the molds or dies must often be inspected and repaired or replaced. The removal and insertion of the molds or dies has typically involved the laborious and time-consuming manipulation of various service fittings and the realignment of the mold or die to resume operations. In any high production operation, the down-time accompanying the change of molds or dies and the associated labor costs must be minimized to maintain the desired productivity. Therefore, a system which contains means for the quick change of a fixture such as a mold or a die in which the fixture can be quickly and securely fastened or released from a work surface is desirable.
Attempts to effect such quick change need by modification of clamping means has been attempted; see for instance the U.S. Pat. Nos.:
______________________________________ 2,940,384 June 16, 1980 Manschuer et al. 4,058,885 November 22, 1977 Bergman 4,354,796 October 19, 1982 Bergman 4,472,127 September 18, 1984 Cyriax et al. 4,555,228 November 26, 1985 Nishiike et al. ______________________________________
However, none of the corresponding structure described therein has been fully satisfactory in meeting said need, particularly in a press such as a trim press.
It is an object of the present invention to provide a positive and simplified registration means for the fixture, that the latter means be part of the clamp structure, and that the fixture comprise the mount plates for punch and die tools of a trim press.
It is a further object of the invention that the described improved and novel means be inexpensive and uncomplicated with respect to manufacture, assembly and use.